print( 'Start ESP32')
from hcsr04 import
from machine import Pin, I2C, PWM
import time 
import ssd1306

buz = PWM(Pin (4))

i2c = I2C(0, scl=Pin (22), sda=Pin(23))

oled_width = 128
oled_height = 64
oled = ssd1306. SSD1306_I2C(oled_width, oled_height, i2c)

ss = HCSR04(trigger_pin=12, echo_pin=14, echo_timeout_us=1000000)

def sound_buz (frequency, duration_ms) :
    buz.freq(freqency)
    buz.duty(512)
    time.sleep(duration_ms / 1000)
    buz.duty(0)

while True:
    distance = ss.distance_cm()
    print(distance)
    oled.fill(0)
    oled.text("distance =" , 5, 10)
    oled.text('{:.2f}'.format(distance),5 ,30)
    oled.show()

if distance <=30:
    sound_buz(700,80)  
else:
    buz.duty(0)

time.sleep(0.1)